1. Field of the Invention
The present invention relates to a viewfinder control unit for visually confirming a picture picked up by a television camera, and to the television camera mounted with the viewfinder control unit.
More particularly, the present invention relates to a viewfinder control unit suitable for controlling a liquid crystal viewfinder integrally mounted on a television camera, and a television camera equipped with the viewfinder control unit.
2. Description of the Related Art
Recently, with the improvement in the characteristics of small-sized liquid crystal display monitors, home video cameras with a built-in image monitor are widely spreading (see, Japanese patent application laid-open No. 8-23466 (1996), for example).
In such a home video camera, the direction of its image monitor changes in conjunction with the movement of the television camera. Thus, a state is always maintained in which the eyes of an operator and the screen of the image monitor face each other.
On the other hand, as for a live camera, typified by a studio television camera, or a portable video camera settled on a tripod, since its image monitor changes the position in connection with the movement of the lens, the camera operator must move his or her face so that it faces the image monitor, or changes the direction of the monitor every time its direction varies.
In addition, since the mounted position and display angle of the image monitor are not always settled in optimum states for the television camera operator to watch, the operator must turn the image monitor manually as needed.
When it is equipped with conventional CRT monitor, even in such a television camera, the problem of hindering viewing every time panning or tilting is made seldom arises. However, using a liquid crystal display as its image monitor presents a problem of requiring more accurate angle adjustment from time to time, which is very tedious. This is because, although the visual characteristics of the liquid crystal display are considerably improved at present, its image quality sharply degrades when images to be monitored deviate from the normal position by more tan certain angle, and hence it cannot achieve its function as a monitor.
In other words, it is desired, every time the direction of the television camera lens is changed by panning and tilting, that the angle of the image monitor be varied so that the image monitor always faces the eyes of the camera operator.
On the other hand, although various techniques are known that detect a particular form or color of a subject to automatically trace its movement (see, Japanese patent application laid-open No. 6-30318 (1994), for example), a technique is not yet known that always trains the image monitor of a television camera on the face of the camera operator. In particular, because panning or tilting or changing the position of a television camera (in the vertical direction) is sometimes made even for a stationary subject (see, FIGS. 10A and 10B), the conventional tracking techniques to a subject cannot be applied to the television camera viewfinder without change.